Hybrid Intelligent Control for Optimal Operation of Shaft Furnace Process

Abstract

The extensively used shaft furnace in the ore concentration industry is an important facility that turns the weak-magnetic low-grade hematite ore into strong-magnetic one. During the operation of the shaft furnace roasting process, the optimal control objective is to control the technique indices, namely the magnetic tube recovery ratio (MTRR) that represents the quality, the efficiency, and the consumption of the product processing, into its targeted ranges. However, due to the complex dynamics between the MTRR and the control loops, such a control objective is by far difficult to achieve by the existing control methods, thus only manual control is adopted. In this paper, a hybrid intelligent control method for the optimal process operation is proposed with the purpose of controlling the technique indices into the desired range by on-line adjusting the set-points of the control loops. The proposed method was applied to the roasting process undertaken by 22 shaft furnaces in the ore concentration plant of Jiuquan Steel & Iron Ltd in China. The application results show that the MTRR is controlled to the targeted range with 2% increase; the faulty working-conditions are eliminated, which boosts the equipment operation ratio by 2.98%, resulting in a raise of 0.57% in the concentrated grade and 2.01% in the metal recovery ratio.